Holding device for spare string trimmer line spools

ABSTRACT

A device to hold a spare spool of trimmer line on a string trimmer while the trimmer is in use. The device has a clamp on its frame&#39;s lower surface ( 22 ) to attach it to the string trimmer&#39;s shaft, and elements ( 44 A,  44 B) on its frame&#39;s upper surface ( 20 ) to retain the spare spool of trimmer line. These elements use the spool&#39;s notched indexing lugs ( 34 A,  34 B) and spring ( 42 ) to retain the spare spool. The spare spool is placed into the device by compressing the spool&#39;s spring ( 42 ) and engaging the spool&#39;s notched indexing lugs ( 34 A,  34 B) onto pins ( 28 A,  28 B) located on curved slotted elements ( 24 A,  25 B) located on the upper surface of the device&#39;s frame ( 20 ).

FIELD OF THE INVENTION

[0001] This invention relates in general to string trimmers used to cut grass and weeds. In particular, the invention relates to a holding device comprising a single member for holding a spare spool of trimmer line on the string trimmer while the string trimmer is in use.

BACKROUND OF THE INVENTION

[0002] Without limiting the scope of the invention, its background is described in connection holding a spare spool of trimmer line on an operating string trimmer.

[0003] String trimmers are the most popular means to cut grass and weeds where larger machines such as lawn mowers cannot go, such as in ditches and along borders. String trimmers use a consumable plastic filament or line to accomplish the cutting action. Since this line is constantly abraded during the operation of the string trimmer, most string trimmers employ a spool that holds a quantity of line and dispenses it to allow continuous operation of the string trimmer.

[0004] There are no means to verify the quantity of line present on the spool without partially disassembling the spool assembly. Many operators of string trimmers, particularly commercial landscapers, use the string trimmers a significant distance from where spare spools are stored. The size of these spare spools is large enough that they will not fit in the pockets of pants. The combination of these factors commonly results in wasted time and effort from walking back to where the spare spools are kept.

[0005] As such, a need exists for a holding device which provides a means to attach a spare spool of line to a string trimmer.

SUMMARY OF THE INVENTION

[0006] The present invention provides for a holding device for spare string trimmer line spools.

[0007] Disclosed in one embodiment is a holding device for spare string trimmer line spools. The holding device comprises a frame having an upper and lower surface. The upper surface of the frame is substantially flat with the exception of three protruding elements. Two of these elements are located at the ends of the frame and curve upward and over the flat portion of the frame, each forming a shallow slot with the open end of the slots facing towards the center of the frame. These slots will accommodate the diameter and thickness of the spool's lower disc. Located in the center of each slot is a pin consisting of a half cylinder with its long axis perpendicular to the flat surface of the frame. This pin does not extend all the way to the flat surface of the frame, but stops a sufficient height above it to provide clearance for the spool's indexing lugs to fit between the bottom of the pin and the flat top surface of the frame.

[0008] The third element protruding from the flat surface of the frame is substantially cross-shaped and located at the center of the frame. The size of this cross-shaped element is such that it will fit into the internal cavity of the spool, locating the spool on the holder. The cross-shaped element further includes a knob-like element located at the vertex of the flat portions of the cross-shaped element. This knob-like element will fit inside and positively locate the spool spring.

[0009] The lower surface of the frame is substantially flat with the exception of two curved members forming a clamp. The inner diameter of the circular area between these two curved members is slightly smaller than the outside diameter of the string trimmer's shaft, causing the curved members to deform slightly and provide clamping force when placed on either side of the string trimmer shaft. This clamp will firmly hold the shaft of the string trimmer at a substantially right angle to the long axis of the frame. The clamp is installed onto the string trimmer shaft by pressing the opening of the clamp onto the string trimmer shaft. Additional clamping action is provided if the user requires by allowing the use of a plastic “wire tie” to encircle the string trimmer shaft and pass over each of two ledges provided for this purpose. These curved ledges are located coaxial to the string trimmer shaft and are located opposite the open end of the clamp members. The ledge's inner surface is substantially coincident to the inner surface of the shaft clamp.

[0010] The spool is retained on the spool holder by placing the spool spring on the knob-like element and pressing downward to compress the spool spring while ensuring that the spool is rotated such that the indexing lugs are on each side of the curved slotted elements. When the indexing disc touches the upper surface of the frame, the spool is rotated so that the notched indexing lugs are under the spool holder's pins and the notches on the spool's indexing lugs are centered under the pins. The spool is then released, and the spool spring pushes the spool upward so that the notches in the indexing lugs engage the pins. The upper surface of the slots will contact the spool lower disc and keep enough compression on the spool spring to keep the spool in place on the spool holder.

[0011] The spool is removed from the holder by reversing the steps taken to place it in the holder.

[0012] An advantage of the present invention includes the ease with which a spool can be placed into or be removed from the holder, and the positive way that the spool is held. Another advantage of the present invention includes the relative ease of manufacturing the spool holder and the low costs associated therewith.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a perspective view of the preferred embodiment of the spare spool holder.

[0014]FIG. 2 is a perspective view of a string trimmer spool.

[0015]FIG. 3 is a perspective view of the spare spool holder positioned above the string trimmers' shaft prior to the holder being installed on the shaft.

[0016]FIG. 4 is a perspective view of the spare spool holder installed on the string trimmer's shaft.

[0017]FIGS. 5 through 8 are perspective views of a spool being installed on the spare spool holder.

[0018]FIG. 9 is a perspective view of an alternate embodiment of the spare spool holder.

[0019]FIG. 10 is a perspective view of an alternate embodiment of the spare spool holder.

[0020]FIG. 11 is a perspective view of an alternate embodiment of the spare spool holder.

REFERENCE NUMERALS IN DRAWINGS

[0021] 18 Holder, spool 20 Frame, upper surface 22 Frame, lower surface   24A Curved, slotted elements   24B   26A Slots   26B   28A Pins   28B 30 Lower disc, spool   32A Indexing lugs   32B   32C   32D   34A Lugs, indexing, notched   34B 36 Element, cross-shaped 38 Cavity, Spool, internal 40 Knob-like element 42 Spring, spool   44A Curved members   44B 46 Shaft, string trimmer 48 Opening clamp   50A Ledges   50B 52 Recess, alternate embodiment 54 Bar, alternate embodiment   56A Arm, alternate embodiment   56B 58 Rung, alternate embodiment 60 Hook, alternate embodiment 80 Spool 64 Split collar, alternate embodiment 66 Hole, alternate embodiment

DETAILED DESCRIPTION OF THE PREFERED EMODIMENTS

[0022] The present invention provides for a holding device for spare string trimmer line spools.

[0023] Disclosed in one embodiment is a holding device for spare string trimmer line spools illustrated in FIG. 1. A typical string trimmer line spool is shown for reference in FIG. 2. The holding device comprises a frame having an upper 20 and lower 22 surface. The upper surface of the frame is substantially flat with the exception of three protruding elements. Two of these elements 24A and 24B are located at the ends of the frame and curve upward and over the flat portion of the frame, each forming a shallow slot 26A, 26B with the open end of the slots facing towards the center of the frame. These slots will accommodate the diameter and thickness of the spool's lower disc 30 illustrated in FIG. 2. Located in the center of each slot is a pin 28A, 28B consisting of a half cylinder with its long axis perpendicular to the flat surface of the frame. This pin does not extend all the way to the flat surface of the frame, but stops a sufficient height above it to provide clearance for the spool's indexing lugs 32A, 32B, 32C, 32D, 34A, 34B to fit between the bottom of the pin and the flat top surface of the frame 20.

[0024] The third element protruding from the flat surface of the frame is substantially cross-shaped and located at the center of the frame 36. The size of this cross-shaped element is such that it will fit into the internal cavity of the spool 38, locating the spool on the holder 18. The cross-shaped element further includes a knob-like element 40 located at the vertex of the flat portions of the cross-shaped element. This knob-like element will fit inside and positively locate the spool spring 42.

[0025] The lower surface 22 of the frame is substantially flat with the exception of two curved members 44A, 44B forming a clamp. The inner diameter of the circular area between these two curved members is slightly smaller than the outside diameter of the sting trimmer's shaft 46, causing the curved members to deform slightly and provide clamping force when placed on either side of the string trimmer shaft. This clamp will firmly hold the shaft of the string trimmer 46 at a substantially right angle to the long axis of the frame. FIGS. 3 and 4 show the installation of the spool holder 18 on the string trimmer shaft 46. The clamp is installed onto the string trimmer shaft by pressing the opening of the clamp 48 onto the string trimmer shaft 46. Additional clamping action is provided if the user requires by allowing the use of a plastic “wire tie” to encircle the string trimmer shaft 46 and pass over each of two ledges 50A, 50B provided for this purpose. These curved ledges are located coaxial to the string trimmer shaft and are located opposite the open end of the clamp members. The ledge's inner surface is substantially coincident to the inner surface of the shaft clamp.

[0026]FIGS. 5, 6, 7, and 8 illustrate the sequence of installing a spare spool 80 in the spool holder 18. The spool is retained on the spool holder by placing the spool spring 42 on the knob-like element 40 and pressing downward to compress the spool spring 42 while ensuring that the spool 80 is rotated such that the indexing lugs 32A, 32B, 32C, 32D, 34A, 34B are on each side of the curved slotted elements 24A, 24B as shown in FIG. 6. When the indexing disc 30 touches the upper surface of the frame 20, the spool 80 is rotated so that the notched indexing lugs 34A, 34B are under the spool holder's pins 28A, 28B and the notches 52A, 52B on the spool's indexing lugs 34A, 34B are centered under the pins 28A, 28B as shown in FIG. 7. The spool is then released, and the spool spring 42 pushes the spool upward so that the notches 52A, 52B in the indexing lugs 34A, 34B engage the pins 28A, 28B. The upper surface of the slots 26A, 26B will contact the spool lower disc 30 and keep enough compression on the spool spring 42 to keep the spool in place on the spool holder as shown in FIG. 8.

DETAILED DESCRIPTION OF ALTERNATE EMBODIMENTS

[0027] One alternate embodiment provides for a holder for spare string trimmer line spools for spools that have indexing lugs but no notches in the lugs as described above in the preferred embodiment. As shown in FIG. 9, this embodiment utilizes a recess 52 in the upper surface of each shallow slot 26A, 26B in place of the pins 28A, 28B used in the preferred embodiment. The indexing lugs 32A, 32B 32C, 32D, 34A, 34B engage the recess instead of the pins 28A, 28B to retain the spare spool 80 on the spool holder 18.

[0028] The operation of this embodiment is identical to the operation of the preferred embodiment except that since there are no notched indexing lugs 34A, 34B, any indexing lug can be placed in the shallow slot and engage the recess to retain the spool.

[0029] This embodiment is more versatile than the preferred embodiment because it can be used with spools with or without notched indexing lugs, but the recess requires a more expensive plastic injection mold to produce than the pin used in the preferred embodiment.

[0030] Another alternate embodiment provides for a holder for spare trimmer spools for spools that have no external indexing lugs. As shown in FIG. 10, this embodiment utilizes a set of arms 56A, 56B extending from the frame 20 a sufficient distance to allow a retaining bar 54 to pass over the spare spool 80 and keep the spool's spring 42 compressed. The arms each have a ladder-rung-like structure with several rungs 58 on each arm. The retaining bar 54 has two ends. Each end forms a hook 60 that snaps onto a rung 58 in such a manner that the retaining bar is held in place but is free to rotate about the axis of the rung. The other end of the retaining bar forms a hook 60 that engages a rung on the opposite arm of the spare spool holder and is held there by the tension of the spool spring 42.

[0031] The plurality of rungs on each arm of the spare trimmer spool holder allows spare trimmer line spools of varying heights to be accommodated by moving the retaining bar up or down the rungs as required.

[0032] In this embodiment of the spare spool holder 80, the spare spool is placed in the holder by centering the spool over the cross-shaped element 36 and pressing down to compress the spool spring 42 as in the preferred embodiment. When the spool spring is compressed, and the spool is touching the upper surface of the frame 20, the retaining bar 54 is rotated over the spool 80, while at the same time the arm opposite the one that the retaining bar is fastened to is pushed slightly outward, away from the spool to allow the retaining bar to swing past the rung corresponding to the rung on the opposite arm that the retaining bar is attached to. The arm being pushed outward is then released, causing the end of the retaining bar to pass between rungs. The spool 80 is then released, so that the spool spring 42 compels the spool to move away from the frame 20. When the spool 80 contacts the retaining bar 54, it pushes the hook 60 on the end of the retaining bar 54 onto the rung 58 above it, holding both the retaining bar and the spool positively in place.

[0033] Another alternate embodiment provides for the curved members 44A, 44B described in the preferred embodiment to be replaced with clamping arrangement utilizing a split collar 64 and a hole 66 to accommodate a threaded fastener as shown in FIG. 11. This embodiment provides a more positive clamping action at the expense of higher manufacturing cost and reduced ease of installation. 

I claim:
 1. A device for holding a spare string trimmer spool on a string trimmer, comprising: (a) a clamping means to hold the device on the string trimmer's shaft, and (b) a frame that utilizes the compression of the spare spool's spring to cause the spool to engage elements of the frame as a means of holding the spool in place whereby the spare spool of trimmer line is securely held on the string trimmer during use of the string trimmer and can be conveniently put into use on the string trimmer when required.
 2. The holder of claim 1 wherein the clamping means comprises a pair of curved members that grip the string trimmer's shaft after the shaft is pushed between the curved members.
 3. The holder of claim 1 wherein a plurality of ledges are attached to the frame as a means to allow plastic wire ties to used to enhance the security of the connection between spare spool holder and the string trimmer's shaft.
 4. The holder of claim 1 wherein the clamping means comprises a split collar and threaded fastener.
 5. The holder of claim 1 wherein the frame employs a plurality of pins to engage the spare spool's notched indexing lugs as a means of positively locating the spare spool on the spare spool holder.
 6. The holder of claim 1 wherein the frame employs a plurality of recesses to engage the spare spool's indexing lugs as a means of positively locating the spare spool on the spare spool holder.
 7. The holder of claim 1 wherein the frame employs a pair of ladder-like members and a retaining bar with hooks on each end to engage the rungs of the ladder-like members as a means of positively locating the spare spool on the spare spool holder.
 8. The holder of claim 1 wherein a cross-shaped member is attached to the said frame as a means of centering and retaining the spare spool on the spare spool holder.
 9. The holder of claim 1 wherein a knob-like element is located on the cross-shaped member as a means of positively locating the spare spool's spring. 